Grinding



"2 sheets-shew 1.

(No Model.)

G. A. MARSH, Jr. GMNDING, sMooTHING, AND PULISHING GLASS.

No. 488,925. Patented Deo. 27, 1892.

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(No Model.) 4

G. A. MARSH, Jr. GRINDING, SMOOTHING, AND POLSBIING` GLASS.

No. 488,925. Patented Deo. 2?;1892.

l-INTTED STATES PATENT OFFICE.

GEORGE AUGUSTUS MARSH, JR., OF SANDUSKY, OHIO.

GRINDING, SMOOTHING, AND POLISHING GLASS.

SPECIFICATION forming part of Letters Patent No. 488,925, dated December27, 1892.

Application filed June 18| 1892. Serial No. 437,123. (No model.)

To all whom t may concern.-

Be it known that I, GEORGE AUGUSTUS MARSH, .I r., a citizen of theUnited States of America, residing at Sandusky, in the county of Erieand State of Ohio, have invented certain new and useful Improvements inAppa ratus for Grinding, Smoothing, and Polishing Glass; and I do herebydeclare the following to be afull, clear, and exact description of theinvention, such as will enable others skilled in the art to which itappertains to make and use the same, reference being had to theaccompanying drawings, and to letters of reference marked thereon, whichform a part of this specication.

This invention relates to improvements in apparatus for grinding,smoothing, and polishing plate glass, and more particularly to theconstruction of the table and sections which form or make up the tabletop, as well as means for exhausting the air therefrom and supplying aliquid thereto; the present application being designed as an improvementupon my previous applications. which were filed February 12,1891, SerialNo. 381,190; September '7, 1891, Serial Nos. 405,009 and 405,010, andSeptember 30, 1891, Serial No. 407,346.

In the accompanying drawings, forming part of this specification: Figure1 is a vertical section of a table for grinding, smoothing and polishingglass, said table being constructed in accordance with my invention.Fig. 2 is an enlarged sectional view of a part of one of the sectionsused in forming the top of the table- Fig. 3 is a perspective view,partly in section, of one of the sections of the top of the table. Fig.4 is a detail perspective view of one corner of a section of the table,showing a portion of one of the lifting bars. Fig. 5 is a detailperspective view of a section of the table showing glass plates ofdiiferent thickness placed thereon. Fig. 6 is a perspective view of thereticulated packing, and Fig. 7 is a sectional view of the stopper suchas is used to closed the apertures in the sections.

The table, preferably a rotary one, is provided with a hollow standardor support, A, the lower end of which enters a suitable box or casing Bhaving a space to receive a packing which can be clamped around thestandard in any suitable manner. This standard at a short distance aboveits lower end and within the box B has an aperture a which formscommunication between the hollow standard and air exhaust pipe A.Longitudinally through the standard passes a water supply pipe O, thelower end of which is secured to the base of the standard, which at thispoint is provided with a downwardly projecting conical portion adaptedto fit within 'a conical depression formed in a block or step D, locatedwithin the box or casing B, said step having an aperture c, whichconnects with the pipe O and into which is passed the water-supply C'which passes without the casing. This block or step may also have anaperture CZ connected with a pipe for supplying a lubricant to thebearing of the standard. The water supply pipel C passes into a chamberc at the upper end of the standard, a packing being provided betweenthis chamber and the hollow part of the standard; and connecting withsaid chamber are a series of distributing pipes E, leading therefrom tothe different sections S which make up the table to I'llo the hollowpart of the standard is connected a pipe F which is connected to the airchambers in each of the sect-ions by branch pipes, and these branchpipes are provided with suitable check-valvesf, and with dependingextensions having removable caps p; these extensions forming traps tocatch any gritty or foreign substance which may be drawn into the pipesby the air-exhaust mechanism.

The water chambers S in the sections S, which receive their supply fromthe distributing pipes E are each provided with a discharge pipe Ghaving a valve g which is spring actuated in one direction, so that thewater which is fed to the chamber under pressure will be discharged whenit attains a certain pressure, the operation of the valve being adjustedby means of a set-screw g.

The table top, as before stat-ed, is made up of a number of sections S,and each section is composed of upper and lower parts L and M, which areseparated or divided into two compartments by a plate of metal N uponthe upper and lower sides of which a suitable ICO packing is placed. Ontheir inner sides the parts L and M have suitable ribs n, n, which arearranged to be one above the other when the parts are brought together,and also with suitable blocks Z which are apertured for the passage ofbolts m used to clamp the parts to each other. The upper part is alsoprovided with downwardly projecting portions which are apertured toconnect with the lower part, and the lower part is provided with similarportions through which the distributing pipes E enter, and at a distancetherefrom this construction is repeated for the attachment of thedischarge pipe G. The bed plate P of the table, as well as the majorportion of said table is made of iron or other suitable metal, and saidbed-plate at intervals is provided with set screws p', which enterapertures in the sections S and form supports therefor. Each section Sisprovided adjacent to its edge with a water channel s, which connectswith the liquid chamber adjacent to the top wall of each section, andthe top wall of each section is provided with raised ribs or supportsupon which the glass to be operated upon will rest indirectly, as inpractice a packing is laid over the top of the sections before theplates of glass are placed thereon. Spaces s are formed between theraised walls so that the air can be exhausted from each section througha single aperture.

From the foregoing description the construction of my presentimprovement will be fully understood.

In grinding, smoothing or polishing plate or sheet glass with thehereinbefore described apparatus my method of operation is as follows: Asuitable packing is placed over each section of the table top and theglass is then placed thereon; water or liquid in suitable quantities isadmitted into the water chamber, which is the upper chamber of eachsection, and passes through the apertures in the channels to the packingadjacent to the margin of each section. When the air is exhausted frombeneath the glass it will be held upon the top of the table byatmospheric pressure; the pressure of the water in the upper chamber maybe ten pounds, more or less, and ordinarily there is not a materialcirculation of said water in the sections until the pressure isincreased beyond the normal resistance of the spring valves. Thestructure being made of metal has great conductive powers, andespecially in polishing glassv it is necessary that the propertemperature should be given to it by slow friction before the polishingcan be carried on rapidly. By my improved structure I can proceed atonce with,

the rapid grinding,smoothiug or-polishing of the glass, as thetemperature of the liquid can be regulated for such purpose. Bysupplying cool Water to the chamber when the glass is too much heated byfriction the water will absorb the heat. When itis desired to heat theglass so that rapid polishing may be proceeded with at once, hot water,or other heating medium, as steam, may be supplied to the upper chamberof the table.

I claim: l. Aglass holding table having a top made up of a plurality ofsections, which are composed of upper and lower portions dividedhorizontally into chambers, the upper chamber having induction andeduction openings, the lower chamber having an opening connected withair exhaust mechanism, and means for connecting the parts of thesections to each other and to a support, substantially as shown, and forthe purpose set forth.

2. A section for a glass holding table made up of upper and lowerportions having an intervening plate, the parts being` connected witheach other and provided with passages which connect with liquid supplypipes and air exhaust pipes, substantially as shown, and for the purposeset forth.

3. A section for aglass holding table made up of upper and lowerportions having an intervening plate, the parts being connected to eachother and provided with passages which connect with liquid supply pipesand air exhaust pipes, the exterior of the upper part having raisedsupports, substantially as shown.

4. A section adapted to form a part of a glassholding table havingregistering inner projecting walls, a dividing plate and packingtherefor, and means for connecting the parts of each section to eachother and to a support, substantially as shown, and for the purpose setforth.

5. In a glass holding table, the combination of a hollow shaft the lowerend thereof being. apertured and inclosed in a suitable chamber to whichan air exhaust pipe is connected, a liquid supply pipe located withinthe hollow standard and connected with a liquid supply, substantially asshown, and for the purpose set forth.

6. In au apparatus for grinding, polishing and smoothing glass, thecombination of a table top and mechanism for holding the glass thereonby atmospheric pressure, aliquid supply pipe leading to the table topand adapted to convey liquid thereto for the purpose set forth, theeduction openings of the sections having spring actuated valves forpermitting a circulation of water in the glass holding table when forcedtherein beyond a predetermined pressure, for the purpose set forth.

7. A glass holding table made up of a series of hollow sectionssupported so that the upper surfaces thereof will be on the same plane,each section having marginal walls with a Water channel and intermediateprojecting portions with spaces between them, and an air exhaust openingcommon to each section, substantially as shown, and for the purpose setforth.

IOO

8. n a glass grinding and polishing table, the combination of a supportmaintaining a top in position, said top being divided horizontally intoair and liquid chambers, pipes connecting said chambers with a shaft,and pipes leading from the shaft, for the purpose set forth.

9. A glass grinding and polishing table having a chamber adjacent to itsupper surface, said chamber being connected with a heating or coolingsource, whereby the glass placed on the table can be cooled or heated,substantially as set forth.

10. A glass grinding or polishing table having a chamber, said chamberbeing connected with a heat supply.

In testimony whereof I afx my signature in presence of two witnesses.

GEORGE AUGUSTUS MARSH, JB..

Witnesses:

LINN W. HULL, L. H. GOODWIN.

